Within about the past five years, wheeled luggage of the type having a box-like body, a pair of wheels, one adjacent each end of the bottom edge of the back wall of the body, and a towing handle that pulls out from adjacent the top edge of the back wall have become immensely popular. Most wheeled luggage of that type has a so-called "add-a-bag" device that enables a user to attach other articles to the luggage, such as a briefcase or a carry-on case or bag. Most add-a-bag arrangements have a strap that is attached to the top wall of the wheeled luggage at one end and has a hook at the other end that when in use hangs partway down the front wall of the bag body. When the luggage is being towed, the article attached to the hook of the add-a-bag strap rests on the then-inclined, upwardly facing front wall of the wheeled luggage with its center of gravity generally over the wheels.
The add-a-bag strap and hook accessory of wheeled luggage must be detachable from the wheeled luggage to avoid causing problems in the baggage-handling operations in airports and, more generally, in any venue in which wheeled luggage is handled and packed with other luggage and the strap and hook can catch on equipment and other articles.
A common way of making the add-a-bag strap and hook detachable has heretofore been by a stock quick-release buckle of the type having a tongue with resilient latch fingers that hook into a socket and are squeezed together to release the fingers. Although connecting and releasing quick-release buckles is generally fairly simple, some dexterity and attention to aiming the tongue into the socket correctly is necessary. Also quick release buckles, which are usually made of plastic, are not very durable and are quite prone to being broken, particularly in airport baggage-handling operations, which are well-known for according luggage somewhat less than tender loving care.
Another previously known type of detachable connection for an add-a-bag strap consists of a headed stud fastened to the top of the bag body and a fitting on the strap that has a keyhole slot for the stud. Installing and removing the plate require two movements of the fitting. Removing the plate is particularly tedious, because the edges of the larger hole of the keyhole slot can catch under the head of the stud, and the user has to maneuver the plate radially of the stud to get the larger hole of the slot to register with the head of the stud so that the fitting can be lifted axially off the stud. When the strap is removed from the stud, the stud becomes a relatively sharp projection from the top wall of the body of the luggage that can damage other baggage.